[sgt/puzzles] / sixteen.c

/*
 * sixteen.c: `16-puzzle', a sliding-tiles jigsaw which differs
 * from the 15-puzzle in that you toroidally rotate a row or column
 * at a time.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <math.h>

#include "puzzles.h"

const char *const game_name = "Sixteen";
const int game_can_configure = TRUE;

#define TILE_SIZE 48
#define BORDER    TILE_SIZE            /* big border to fill with arrows */
#define HIGHLIGHT_WIDTH (TILE_SIZE / 20)
#define COORD(x)  ( (x) * TILE_SIZE + BORDER )
#define FROMCOORD(x)  ( ((x) - BORDER + 2*TILE_SIZE) / TILE_SIZE - 2 )

#define ANIM_TIME 0.13F
#define FLASH_FRAME 0.13F

#define X(state, i) ( (i) % (state)->w )
#define Y(state, i) ( (i) / (state)->w )
#define C(state, x, y) ( (y) * (state)->w + (x) )

enum {
    COL_BACKGROUND,
    COL_TEXT,
    COL_HIGHLIGHT,
    COL_LOWLIGHT,
    NCOLOURS
};

struct game_params {
    int w, h;
};

struct game_state {
    int w, h, n;
    int *tiles;
    int completed;
    int movecount;
    int last_movement_sense;
};

game_params *default_params(void)
{
    game_params *ret = snew(game_params);

    ret->w = ret->h = 4;

    return ret;
}

int game_fetch_preset(int i, char **name, game_params **params)
{
    game_params *ret;
    int w, h;
    char buf[80];

    switch (i) {
      case 0: w = 3, h = 3; break;
      case 1: w = 4, h = 3; break;
      case 2: w = 4, h = 4; break;
      case 3: w = 5, h = 4; break;
      case 4: w = 5, h = 5; break;
      default: return FALSE;
    }

    sprintf(buf, "%dx%d", w, h);
    *name = dupstr(buf);
    *params = ret = snew(game_params);
    ret->w = w;
    ret->h = h;
    return TRUE;
}

void free_params(game_params *params)
{
    sfree(params);
}

game_params *dup_params(game_params *params)
{
    game_params *ret = snew(game_params);
    *ret = *params;		       /* structure copy */
    return ret;
}

config_item *game_configure(game_params *params)
{
    config_item *ret;
    char buf[80];

    ret = snewn(3, config_item);

    ret[0].name = "Width";
    ret[0].type = C_STRING;
    sprintf(buf, "%d", params->w);
    ret[0].sval = dupstr(buf);
    ret[0].ival = 0;

    ret[1].name = "Height";
    ret[1].type = C_STRING;
    sprintf(buf, "%d", params->h);
    ret[1].sval = dupstr(buf);
    ret[1].ival = 0;

    ret[2].name = NULL;
    ret[2].type = C_END;
    ret[2].sval = NULL;
    ret[2].ival = 0;

    return ret;
}

game_params *custom_params(config_item *cfg)
{
    game_params *ret = snew(game_params);

    ret->w = atoi(cfg[0].sval);
    ret->h = atoi(cfg[1].sval);

    return ret;
}

char *validate_params(game_params *params)
{
    if (params->w < 2 && params->h < 2)
	return "Width and height must both be at least two";

    return NULL;
}

int perm_parity(int *perm, int n)
{
    int i, j, ret;

    ret = 0;

    for (i = 0; i < n-1; i++)
        for (j = i+1; j < n; j++)
            if (perm[i] > perm[j])
                ret = !ret;

    return ret;
}

char *new_game_seed(game_params *params, random_state *rs)
{
    int stop, n, i, x;
    int x1, x2, p1, p2;
    int *tiles, *used;
    char *ret;
    int retlen;

    n = params->w * params->h;

    tiles = snewn(n, int);
    used = snewn(n, int);

    for (i = 0; i < n; i++) {
        tiles[i] = -1;
        used[i] = FALSE;
    }

    /*
     * If both dimensions are odd, there is a parity constraint.
     */
    if (params->w & params->h & 1)
        stop = 2;
    else
        stop = 0;

    /*
     * Place everything except (possibly) the last two tiles.
     */
    for (x = 0, i = n; i > stop; i--) {
        int k = i > 1 ? random_upto(rs, i) : 0;
        int j;

        for (j = 0; j < n; j++)
            if (!used[j] && (k-- == 0))
                break;

        assert(j < n && !used[j]);
        used[j] = TRUE;

        while (tiles[x] >= 0)
            x++;
        assert(x < n);
        tiles[x] = j;
    }

    if (stop) {
        /*
         * Find the last two locations, and the last two pieces.
         */
        while (tiles[x] >= 0)
            x++;
        assert(x < n);
        x1 = x;
        x++;
        while (tiles[x] >= 0)
            x++;
        assert(x < n);
        x2 = x;

        for (i = 0; i < n; i++)
            if (!used[i])
                break;
        p1 = i;
        for (i = p1+1; i < n; i++)
            if (!used[i])
                break;
        p2 = i;

        /*
         * Try the last two tiles one way round. If that fails, swap
         * them.
         */
        tiles[x1] = p1;
        tiles[x2] = p2;
        if (perm_parity(tiles, n) != 0) {
            tiles[x1] = p2;
            tiles[x2] = p1;
            assert(perm_parity(tiles, n) == 0);
        }
    }

    /*
     * Now construct the game seed, by describing the tile array as
     * a simple sequence of comma-separated integers.
     */
    ret = NULL;
    retlen = 0;
    for (i = 0; i < n; i++) {
        char buf[80];
        int k;

        k = sprintf(buf, "%d,", tiles[i]+1);

        ret = sresize(ret, retlen + k + 1, char);
        strcpy(ret + retlen, buf);
        retlen += k;
    }
    ret[retlen-1] = '\0';              /* delete last comma */

    sfree(tiles);
    sfree(used);

    return ret;
}


char *validate_seed(game_params *params, char *seed)
{
    char *p, *err;
    int i, area;
    int *used;

    area = params->w * params->h;
    p = seed;
    err = NULL;

    used = snewn(area, int);
    for (i = 0; i < area; i++)
	used[i] = FALSE;

    for (i = 0; i < area; i++) {
	char *q = p;
	int n;

	if (*p < '0' || *p > '9') {
	    err = "Not enough numbers in string";
	    goto leave;
	}
	while (*p >= '0' && *p <= '9')
	    p++;
	if (i < area-1 && *p != ',') {
	    err = "Expected comma after number";
	    goto leave;
	}
	else if (i == area-1 && *p) {
	    err = "Excess junk at end of string";
	    goto leave;
	}
	n = atoi(q);
	if (n < 1 || n > area) {
	    err = "Number out of range";
	    goto leave;
	}
	if (used[n-1]) {
	    err = "Number used twice";
	    goto leave;
	}
	used[n-1] = TRUE;

	if (*p) p++;		       /* eat comma */
    }

    leave:
    sfree(used);
    return err;
}

game_state *new_game(game_params *params, char *seed)
{
    game_state *state = snew(game_state);
    int i;
    char *p;

    state->w = params->w;
    state->h = params->h;
    state->n = params->w * params->h;
    state->tiles = snewn(state->n, int);

    p = seed;
    i = 0;
    for (i = 0; i < state->n; i++) {
        assert(*p);
        state->tiles[i] = atoi(p);
        while (*p && *p != ',')
            p++;
        if (*p) p++;                   /* eat comma */
    }
    assert(!*p);

    state->completed = state->movecount = 0;
    state->last_movement_sense = 0;

    return state;
}

game_state *dup_game(game_state *state)
{
    game_state *ret = snew(game_state);

    ret->w = state->w;
    ret->h = state->h;
    ret->n = state->n;
    ret->tiles = snewn(state->w * state->h, int);
    memcpy(ret->tiles, state->tiles, state->w * state->h * sizeof(int));
    ret->completed = state->completed;
    ret->movecount = state->movecount;
    ret->last_movement_sense = state->last_movement_sense;

    return ret;
}

void free_game(game_state *state)
{
    sfree(state);
}

game_ui *new_ui(game_state *state)
{
    return NULL;
}

void free_ui(game_ui *ui)
{
}

game_state *make_move(game_state *from, game_ui *ui, int x, int y, int button)
{
    int cx, cy;
    int dx, dy, tx, ty, n;
    game_state *ret;

    if (button != LEFT_BUTTON)
        return NULL;

    cx = FROMCOORD(x);
    cy = FROMCOORD(y);
    if (cx == -1 && cy >= 0 && cy < from->h)
        n = from->w, dx = +1, dy = 0;
    else if (cx == from->w && cy >= 0 && cy < from->h)
        n = from->w, dx = -1, dy = 0;
    else if (cy == -1 && cx >= 0 && cx < from->w)
        n = from->h, dy = +1, dx = 0;
    else if (cy == from->h && cx >= 0 && cx < from->w)
        n = from->h, dy = -1, dx = 0;
    else
        return NULL;                   /* invalid click location */

    ret = dup_game(from);

    do {
        cx += dx;
        cy += dy;
        tx = (cx + dx + from->w) % from->w;
        ty = (cy + dy + from->h) % from->h;
        ret->tiles[C(ret, cx, cy)] = from->tiles[C(from, tx, ty)];
    } while (--n > 0);

    ret->movecount++;

    ret->last_movement_sense = -(dx+dy);

    /*
     * See if the game has been completed.
     */
    if (!ret->completed) {
        ret->completed = ret->movecount;
        for (n = 0; n < ret->n; n++)
            if (ret->tiles[n] != n+1)
                ret->completed = FALSE;
    }

    return ret;
}

/* ----------------------------------------------------------------------
 * Drawing routines.
 */

struct game_drawstate {
    int started;
    int w, h, bgcolour;
    int *tiles;
};

void game_size(game_params *params, int *x, int *y)
{
    *x = TILE_SIZE * params->w + 2 * BORDER;
    *y = TILE_SIZE * params->h + 2 * BORDER;
}

float *game_colours(frontend *fe, game_state *state, int *ncolours)
{
    float *ret = snewn(3 * NCOLOURS, float);
    int i;
    float max;

    frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]);

    /*
     * Drop the background colour so that the highlight is
     * noticeably brighter than it while still being under 1.
     */
    max = ret[COL_BACKGROUND*3];
    for (i = 1; i < 3; i++)
        if (ret[COL_BACKGROUND*3+i] > max)
            max = ret[COL_BACKGROUND*3+i];
    if (max * 1.2F > 1.0F) {
        for (i = 0; i < 3; i++)
            ret[COL_BACKGROUND*3+i] /= (max * 1.2F);
    }

    for (i = 0; i < 3; i++) {
        ret[COL_HIGHLIGHT * 3 + i] = ret[COL_BACKGROUND * 3 + i] * 1.2F;
        ret[COL_LOWLIGHT * 3 + i] = ret[COL_BACKGROUND * 3 + i] * 0.8F;
        ret[COL_TEXT * 3 + i] = 0.0;
    }

    *ncolours = NCOLOURS;
    return ret;
}

game_drawstate *game_new_drawstate(game_state *state)
{
    struct game_drawstate *ds = snew(struct game_drawstate);
    int i;

    ds->started = FALSE;
    ds->w = state->w;
    ds->h = state->h;
    ds->bgcolour = COL_BACKGROUND;
    ds->tiles = snewn(ds->w*ds->h, int);
    for (i = 0; i < ds->w*ds->h; i++)
        ds->tiles[i] = -1;

    return ds;
}

void game_free_drawstate(game_drawstate *ds)
{
    sfree(ds->tiles);
    sfree(ds);
}

static void draw_tile(frontend *fe, game_state *state, int x, int y,
                      int tile, int flash_colour)
{
    if (tile == 0) {
        draw_rect(fe, x, y, TILE_SIZE, TILE_SIZE,
                  flash_colour);
    } else {
        int coords[6];
        char str[40];

        coords[0] = x + TILE_SIZE - 1;
        coords[1] = y + TILE_SIZE - 1;
        coords[2] = x + TILE_SIZE - 1;
        coords[3] = y;
        coords[4] = x;
        coords[5] = y + TILE_SIZE - 1;
        draw_polygon(fe, coords, 3, TRUE, COL_LOWLIGHT);
        draw_polygon(fe, coords, 3, FALSE, COL_LOWLIGHT);

        coords[0] = x;
        coords[1] = y;
        draw_polygon(fe, coords, 3, TRUE, COL_HIGHLIGHT);
        draw_polygon(fe, coords, 3, FALSE, COL_HIGHLIGHT);

        draw_rect(fe, x + HIGHLIGHT_WIDTH, y + HIGHLIGHT_WIDTH,
                  TILE_SIZE - 2*HIGHLIGHT_WIDTH, TILE_SIZE - 2*HIGHLIGHT_WIDTH,
                  flash_colour);

        sprintf(str, "%d", tile);
        draw_text(fe, x + TILE_SIZE/2, y + TILE_SIZE/2,
                  FONT_VARIABLE, TILE_SIZE/3, ALIGN_VCENTRE | ALIGN_HCENTRE,
                  COL_TEXT, str);
    }
    draw_update(fe, x, y, TILE_SIZE, TILE_SIZE);
}

static void draw_arrow(frontend *fe, int x, int y, int xdx, int xdy)
{
    int coords[14];
    int ydy = -xdx, ydx = xdy;

#define POINT(n, xx, yy) ( \
    coords[2*(n)+0] = x + (xx)*xdx + (yy)*ydx, \
    coords[2*(n)+1] = y + (xx)*xdy + (yy)*ydy)

    POINT(0, TILE_SIZE / 2, 3 * TILE_SIZE / 4);   /* top of arrow */
    POINT(1, 3 * TILE_SIZE / 4, TILE_SIZE / 2);   /* right corner */
    POINT(2, 5 * TILE_SIZE / 8, TILE_SIZE / 2);   /* right concave */
    POINT(3, 5 * TILE_SIZE / 8, TILE_SIZE / 4);   /* bottom right */
    POINT(4, 3 * TILE_SIZE / 8, TILE_SIZE / 4);   /* bottom left */
    POINT(5, 3 * TILE_SIZE / 8, TILE_SIZE / 2);   /* left concave */
    POINT(6,     TILE_SIZE / 4, TILE_SIZE / 2);   /* left corner */

    draw_polygon(fe, coords, 7, TRUE, COL_LOWLIGHT);
    draw_polygon(fe, coords, 7, FALSE, COL_TEXT);
}

void game_redraw(frontend *fe, game_drawstate *ds, game_state *oldstate,
                 game_state *state, game_ui *ui,
                 float animtime, float flashtime)
{
    int i, bgcolour;

    if (flashtime > 0) {
        int frame = (int)(flashtime / FLASH_FRAME);
        bgcolour = (frame % 2 ? COL_LOWLIGHT : COL_HIGHLIGHT);
    } else
        bgcolour = COL_BACKGROUND;

    if (!ds->started) {
        int coords[6];

	draw_rect(fe, 0, 0,
		  TILE_SIZE * state->w + 2 * BORDER,
		  TILE_SIZE * state->h + 2 * BORDER, COL_BACKGROUND);
	draw_update(fe, 0, 0,
		    TILE_SIZE * state->w + 2 * BORDER,
		    TILE_SIZE * state->h + 2 * BORDER);

        /*
         * Recessed area containing the whole puzzle.
         */
        coords[0] = COORD(state->w) + HIGHLIGHT_WIDTH - 1;
        coords[1] = COORD(state->h) + HIGHLIGHT_WIDTH - 1;
        coords[2] = COORD(state->w) + HIGHLIGHT_WIDTH - 1;
        coords[3] = COORD(0) - HIGHLIGHT_WIDTH;
        coords[4] = COORD(0) - HIGHLIGHT_WIDTH;
        coords[5] = COORD(state->h) + HIGHLIGHT_WIDTH - 1;
        draw_polygon(fe, coords, 3, TRUE, COL_HIGHLIGHT);
        draw_polygon(fe, coords, 3, FALSE, COL_HIGHLIGHT);

        coords[1] = COORD(0) - HIGHLIGHT_WIDTH;
        coords[0] = COORD(0) - HIGHLIGHT_WIDTH;
        draw_polygon(fe, coords, 3, TRUE, COL_LOWLIGHT);
        draw_polygon(fe, coords, 3, FALSE, COL_LOWLIGHT);

        /*
         * Arrows for making moves.
         */
        for (i = 0; i < state->w; i++) {
            draw_arrow(fe, COORD(i), COORD(0), +1, 0);
            draw_arrow(fe, COORD(i+1), COORD(state->h), -1, 0);
        }
        for (i = 0; i < state->h; i++) {
            draw_arrow(fe, COORD(state->w), COORD(i), 0, +1);
            draw_arrow(fe, COORD(0), COORD(i+1), 0, -1);
        }

        ds->started = TRUE;
    }

    /*
     * Now draw each tile.
     */

    clip(fe, COORD(0), COORD(0), TILE_SIZE*state->w, TILE_SIZE*state->h);

    for (i = 0; i < state->n; i++) {
	int t, t0;
	/*
	 * Figure out what should be displayed at this
	 * location. It's either a simple tile, or it's a
	 * transition between two tiles (in which case we say
	 * -1 because it must always be drawn).
	 */

	if (oldstate && oldstate->tiles[i] != state->tiles[i])
	    t = -1;
	else
	    t = state->tiles[i];

	t0 = t;

	if (ds->bgcolour != bgcolour ||   /* always redraw when flashing */
	    ds->tiles[i] != t || ds->tiles[i] == -1 || t == -1) {
	    int x, y, x2, y2;

	    /*
	     * Figure out what to _actually_ draw, and where to
	     * draw it.
	     */
	    if (t == -1) {
		int x0, y0, x1, y1, dx, dy;
		int j;
		float c;
		int sense;

		if (oldstate && state->movecount < oldstate->movecount)
		    sense = -oldstate->last_movement_sense;
		else
		    sense = state->last_movement_sense;

		t = state->tiles[i];

		/*
		 * FIXME: must be prepared to draw a double
		 * tile in some situations.
		 */

		/*
		 * Find the coordinates of this tile in the old and
		 * new states.
		 */
		x1 = COORD(X(state, i));
		y1 = COORD(Y(state, i));
		for (j = 0; j < oldstate->n; j++)
		    if (oldstate->tiles[j] == state->tiles[i])
			break;
		assert(j < oldstate->n);
		x0 = COORD(X(state, j));
		y0 = COORD(Y(state, j));

		dx = (x1 - x0);
		if (dx != 0 &&
		    dx != TILE_SIZE * sense) {
		    dx = (dx < 0 ? dx + TILE_SIZE * state->w :
			  dx - TILE_SIZE * state->w);
		    assert(abs(dx) == TILE_SIZE);
		}
		dy = (y1 - y0);
		if (dy != 0 &&
		    dy != TILE_SIZE * sense) {
		    dy = (dy < 0 ? dy + TILE_SIZE * state->h :
			  dy - TILE_SIZE * state->h);
		    assert(abs(dy) == TILE_SIZE);
		}

		c = (animtime / ANIM_TIME);
		if (c < 0.0F) c = 0.0F;
		if (c > 1.0F) c = 1.0F;

		x = x0 + (int)(c * dx);
		y = y0 + (int)(c * dy);
		x2 = x1 - dx + (int)(c * dx);
		y2 = y1 - dy + (int)(c * dy);
	    } else {
		x = COORD(X(state, i));
		y = COORD(Y(state, i));
		x2 = y2 = -1;
	    }

	    draw_tile(fe, state, x, y, t, bgcolour);
	    if (x2 != -1 || y2 != -1)
		draw_tile(fe, state, x2, y2, t, bgcolour);
	}
	ds->tiles[i] = t0;
    }

    unclip(fe);

    ds->bgcolour = bgcolour;

    /*
     * Update the status bar.
     */
    {
	char statusbuf[256];

        /*
         * Don't show the new status until we're also showing the
         * new _state_ - after the game animation is complete.
         */
        if (oldstate)
            state = oldstate;

	sprintf(statusbuf, "%sMoves: %d",
		(state->completed ? "COMPLETED! " : ""),
		(state->completed ? state->completed : state->movecount));

	status_bar(fe, statusbuf);
    }
}

float game_anim_length(game_state *oldstate, game_state *newstate)
{
    return ANIM_TIME;
}

float game_flash_length(game_state *oldstate, game_state *newstate)
{
    if (!oldstate->completed && newstate->completed)
        return 2 * FLASH_FRAME;
    else
        return 0.0F;
}

int game_wants_statusbar(void)
{
    return TRUE;
}
Commit	Line	Data
4efb3868	1	/*
	2	* sixteen.c: `16-puzzle', a sliding-tiles jigsaw which differs
	3	* from the 15-puzzle in that you toroidally rotate a row or column
	4	* at a time.
	5	*/
	6
	7	#include <stdio.h>
	8	#include <stdlib.h>
	9	#include <string.h>
	10	#include <assert.h>
	11	#include <math.h>
	12
	13	#include "puzzles.h"
	14
	15	const char *const game_name = "Sixteen";
c8230524	16	const int game_can_configure = TRUE;
4efb3868	17
	18	#define TILE_SIZE 48
	19	#define BORDER TILE_SIZE /* big border to fill with arrows */
	20	#define HIGHLIGHT_WIDTH (TILE_SIZE / 20)
	21	#define COORD(x) ( (x) * TILE_SIZE + BORDER )
	22	#define FROMCOORD(x) ( ((x) - BORDER + 2*TILE_SIZE) / TILE_SIZE - 2 )
	23
8c1fd974	24	#define ANIM_TIME 0.13F
8c1fd974	25	#define FLASH_FRAME 0.13F
4efb3868	26
	27	#define X(state, i) ( (i) % (state)->w )
	28	#define Y(state, i) ( (i) / (state)->w )
	29	#define C(state, x, y) ( (y) * (state)->w + (x) )
	30
	31	enum {
	32	COL_BACKGROUND,
	33	COL_TEXT,
	34	COL_HIGHLIGHT,
	35	COL_LOWLIGHT,
	36	NCOLOURS
	37	};
	38
	39	struct game_params {
	40	int w, h;
	41	};
	42
	43	struct game_state {
	44	int w, h, n;
	45	int *tiles;
	46	int completed;
fd1a1a2b	47	int movecount;
c8230524	48	int last_movement_sense;
4efb3868	49	};
	50
	51	game_params *default_params(void)
	52	{
	53	game_params *ret = snew(game_params);
	54
	55	ret->w = ret->h = 4;
	56
	57	return ret;
	58	}
	59
	60	int game_fetch_preset(int i, char name, game_params params)
	61	{
	62	game_params *ret;
	63	int w, h;
	64	char buf[80];
	65
	66	switch (i) {
	67	case 0: w = 3, h = 3; break;
	68	case 1: w = 4, h = 3; break;
	69	case 2: w = 4, h = 4; break;
	70	case 3: w = 5, h = 4; break;
	71	case 4: w = 5, h = 5; break;
	72	default: return FALSE;
	73	}
	74
	75	sprintf(buf, "%dx%d", w, h);
	76	*name = dupstr(buf);
	77	*params = ret = snew(game_params);
	78	ret->w = w;
	79	ret->h = h;
	80	return TRUE;
	81	}
	82
	83	void free_params(game_params *params)
	84	{
	85	sfree(params);
	86	}
	87
	88	game_params dup_params(game_params params)
	89	{
	90	game_params *ret = snew(game_params);
	91	ret = params; /* structure copy */
	92	return ret;
	93	}
	94
c8230524	95	config_item game_configure(game_params params)
	96	{
	97	config_item *ret;
	98	char buf[80];
	99
	100	ret = snewn(3, config_item);
	101
	102	ret[0].name = "Width";
95709966	103	ret[0].type = C_STRING;
c8230524	104	sprintf(buf, "%d", params->w);
	105	ret[0].sval = dupstr(buf);
	106	ret[0].ival = 0;
	107
	108	ret[1].name = "Height";
95709966	109	ret[1].type = C_STRING;
c8230524	110	sprintf(buf, "%d", params->h);
	111	ret[1].sval = dupstr(buf);
	112	ret[1].ival = 0;
	113
	114	ret[2].name = NULL;
95709966	115	ret[2].type = C_END;
c8230524	116	ret[2].sval = NULL;
	117	ret[2].ival = 0;
	118
	119	return ret;
	120	}
	121
	122	game_params custom_params(config_item cfg)
	123	{
	124	game_params *ret = snew(game_params);
	125
	126	ret->w = atoi(cfg[0].sval);
	127	ret->h = atoi(cfg[1].sval);
	128
	129	return ret;
	130	}
	131
	132	char validate_params(game_params params)
	133	{
	134	if (params->w < 2 && params->h < 2)
	135	return "Width and height must both be at least two";
	136
	137	return NULL;
	138	}
	139
4efb3868	140	int perm_parity(int *perm, int n)
	141	{
	142	int i, j, ret;
	143
	144	ret = 0;
	145
	146	for (i = 0; i < n-1; i++)
	147	for (j = i+1; j < n; j++)
	148	if (perm[i] > perm[j])
	149	ret = !ret;
	150
	151	return ret;
	152	}
	153
48d70ca9	154	char new_game_seed(game_params params, random_state *rs)
4efb3868	155	{
	156	int stop, n, i, x;
	157	int x1, x2, p1, p2;
	158	int tiles, used;
	159	char *ret;
	160	int retlen;
	161
	162	n = params->w * params->h;
	163
	164	tiles = snewn(n, int);
	165	used = snewn(n, int);
	166
	167	for (i = 0; i < n; i++) {
	168	tiles[i] = -1;
	169	used[i] = FALSE;
	170	}
	171
	172	/*
	173	* If both dimensions are odd, there is a parity constraint.
	174	*/
	175	if (params->w & params->h & 1)
	176	stop = 2;
	177	else
	178	stop = 0;
	179
	180	/*
	181	* Place everything except (possibly) the last two tiles.
	182	*/
	183	for (x = 0, i = n; i > stop; i--) {
48d70ca9	184	int k = i > 1 ? random_upto(rs, i) : 0;
4efb3868	185	int j;
	186
	187	for (j = 0; j < n; j++)
	188	if (!used[j] && (k-- == 0))
	189	break;
	190
	191	assert(j < n && !used[j]);
	192	used[j] = TRUE;
	193
	194	while (tiles[x] >= 0)
	195	x++;
	196	assert(x < n);
	197	tiles[x] = j;
	198	}
	199
	200	if (stop) {
	201	/*
	202	* Find the last two locations, and the last two pieces.
	203	*/
	204	while (tiles[x] >= 0)
	205	x++;
	206	assert(x < n);
	207	x1 = x;
	208	x++;
	209	while (tiles[x] >= 0)
	210	x++;
	211	assert(x < n);
	212	x2 = x;
	213
	214	for (i = 0; i < n; i++)
	215	if (!used[i])
	216	break;
	217	p1 = i;
	218	for (i = p1+1; i < n; i++)
	219	if (!used[i])
	220	break;
	221	p2 = i;
	222
	223	/*
	224	* Try the last two tiles one way round. If that fails, swap
	225	* them.
	226	*/
	227	tiles[x1] = p1;
	228	tiles[x2] = p2;
	229	if (perm_parity(tiles, n) != 0) {
	230	tiles[x1] = p2;
	231	tiles[x2] = p1;
	232	assert(perm_parity(tiles, n) == 0);
	233	}
	234	}
	235
	236	/*
	237	* Now construct the game seed, by describing the tile array as
	238	* a simple sequence of comma-separated integers.
	239	*/
	240	ret = NULL;
	241	retlen = 0;
	242	for (i = 0; i < n; i++) {
	243	char buf[80];
	244	int k;
	245
	246	k = sprintf(buf, "%d,", tiles[i]+1);
	247
	248	ret = sresize(ret, retlen + k + 1, char);
249	strcpy(ret + retlen, buf);
250	retlen += k;
251	}
252	ret[retlen-1] = '\0'; /* delete last comma */
253
254	sfree(tiles);
255	sfree(used);
256
257	return ret;
258	}
259
5928817c	260
	261	char validate_seed(game_params params, char *seed)
	262	{
	263	char p, err;
	264	int i, area;
	265	int *used;
	266
	267	area = params->w * params->h;
	268	p = seed;
	269	err = NULL;
	270
	271	used = snewn(area, int);
	272	for (i = 0; i < area; i++)
	273	used[i] = FALSE;
	274
	275	for (i = 0; i < area; i++) {
	276	char *q = p;
	277	int n;
	278
	279	if (p < '0' \|\| p > '9') {
	280	err = "Not enough numbers in string";
	281	goto leave;
	282	}
	283	while (p >= '0' && p <= '9')
	284	p++;
	285	if (i < area-1 && *p != ',') {
	286	err = "Expected comma after number";
	287	goto leave;
	288	}
	289	else if (i == area-1 && *p) {
	290	err = "Excess junk at end of string";
	291	goto leave;
	292	}
	293	n = atoi(q);
	294	if (n < 1 \|\| n > area) {
	295	err = "Number out of range";
	296	goto leave;
	297	}
	298	if (used[n-1]) {
	299	err = "Number used twice";
	300	goto leave;
	301	}
	302	used[n-1] = TRUE;
	303
	304	if (p) p++; / eat comma */
	305	}
	306
	307	leave:
	308	sfree(used);
	309	return err;
	310	}
	311
4efb3868	312	game_state new_game(game_params params, char *seed)
	313	{
	314	game_state *state = snew(game_state);
	315	int i;
	316	char *p;
	317
	318	state->w = params->w;
	319	state->h = params->h;
	320	state->n = params->w * params->h;
	321	state->tiles = snewn(state->n, int);
	322
	323	p = seed;
	324	i = 0;
	325	for (i = 0; i < state->n; i++) {
	326	assert(*p);
	327	state->tiles[i] = atoi(p);
	328	while (p && p != ',')
	329	p++;
	330	if (p) p++; / eat comma */
	331	}
	332	assert(!*p);
	333
fd1a1a2b	334	state->completed = state->movecount = 0;
c8230524	335	state->last_movement_sense = 0;
4efb3868	336
	337	return state;
	338	}
	339
	340	game_state dup_game(game_state state)
	341	{
	342	game_state *ret = snew(game_state);
	343
	344	ret->w = state->w;
	345	ret->h = state->h;
	346	ret->n = state->n;
	347	ret->tiles = snewn(state->w * state->h, int);
	348	memcpy(ret->tiles, state->tiles, state->w * state->h * sizeof(int));
	349	ret->completed = state->completed;
fd1a1a2b	350	ret->movecount = state->movecount;
c8230524	351	ret->last_movement_sense = state->last_movement_sense;
4efb3868	352
	353	return ret;
	354	}
	355
	356	void free_game(game_state *state)
	357	{
	358	sfree(state);
	359	}
	360
74a4e547	361	game_ui new_ui(game_state state)
	362	{
	363	return NULL;
	364	}
	365
	366	void free_ui(game_ui *ui)
	367	{
	368	}
	369
	370	game_state make_move(game_state from, game_ui *ui, int x, int y, int button)
4efb3868	371	{
	372	int cx, cy;
	373	int dx, dy, tx, ty, n;
	374	game_state *ret;
	375
	376	if (button != LEFT_BUTTON)
	377	return NULL;
	378
	379	cx = FROMCOORD(x);
	380	cy = FROMCOORD(y);
	381	if (cx == -1 && cy >= 0 && cy < from->h)
	382	n = from->w, dx = +1, dy = 0;
	383	else if (cx == from->w && cy >= 0 && cy < from->h)
	384	n = from->w, dx = -1, dy = 0;
	385	else if (cy == -1 && cx >= 0 && cx < from->w)
	386	n = from->h, dy = +1, dx = 0;
	387	else if (cy == from->h && cx >= 0 && cx < from->w)
	388	n = from->h, dy = -1, dx = 0;
	389	else
	390	return NULL; /* invalid click location */
	391
	392	ret = dup_game(from);
	393
	394	do {
	395	cx += dx;
	396	cy += dy;
	397	tx = (cx + dx + from->w) % from->w;
	398	ty = (cy + dy + from->h) % from->h;
	399	ret->tiles[C(ret, cx, cy)] = from->tiles[C(from, tx, ty)];
	400	} while (--n > 0);
	401
fd1a1a2b	402	ret->movecount++;
fd1a1a2b	403
c8230524	404	ret->last_movement_sense = -(dx+dy);
c8230524	405
4efb3868	406	/*
	407	* See if the game has been completed.
	408	*/
	409	if (!ret->completed) {
fd1a1a2b	410	ret->completed = ret->movecount;
4efb3868	411	for (n = 0; n < ret->n; n++)
	412	if (ret->tiles[n] != n+1)
	413	ret->completed = FALSE;
	414	}
	415
	416	return ret;
	417	}
	418
	419	/* ----------------------------------------------------------------------
	420	* Drawing routines.
	421	*/
	422
	423	struct game_drawstate {
	424	int started;
	425	int w, h, bgcolour;
	426	int *tiles;
	427	};
	428
	429	void game_size(game_params params, int x, int *y)
	430	{
	431	x = TILE_SIZE params->w + 2 * BORDER;
	432	y = TILE_SIZE params->h + 2 * BORDER;
	433	}
	434
	435	float game_colours(frontend fe, game_state state, int ncolours)
	436	{
	437	float ret = snewn(3 NCOLOURS, float);
	438	int i;
	439	float max;
	440
	441	frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]);
	442
	443	/*
	444	* Drop the background colour so that the highlight is
	445	* noticeably brighter than it while still being under 1.
	446	*/
	447	max = ret[COL_BACKGROUND*3];
	448	for (i = 1; i < 3; i++)
	449	if (ret[COL_BACKGROUND*3+i] > max)
	450	max = ret[COL_BACKGROUND*3+i];
	451	if (max * 1.2F > 1.0F) {
	452	for (i = 0; i < 3; i++)
	453	ret[COL_BACKGROUND3+i] /= (max 1.2F);
	454	}
	455
	456	for (i = 0; i < 3; i++) {
	457	ret[COL_HIGHLIGHT * 3 + i] = ret[COL_BACKGROUND * 3 + i] * 1.2F;
	458	ret[COL_LOWLIGHT * 3 + i] = ret[COL_BACKGROUND * 3 + i] * 0.8F;
	459	ret[COL_TEXT * 3 + i] = 0.0;
	460	}
	461
	462	*ncolours = NCOLOURS;
	463	return ret;
	464	}
	465
	466	game_drawstate game_new_drawstate(game_state state)
	467	{
	468	struct game_drawstate *ds = snew(struct game_drawstate);
	469	int i;
	470
	471	ds->started = FALSE;
	472	ds->w = state->w;
	473	ds->h = state->h;
	474	ds->bgcolour = COL_BACKGROUND;
475	ds->tiles = snewn(ds->w*ds->h, int);
476	for (i = 0; i < ds->w*ds->h; i++)
477	ds->tiles[i] = -1;
478
479	return ds;
480	}
481
482	void game_free_drawstate(game_drawstate *ds)
483	{
484	sfree(ds->tiles);
485	sfree(ds);
486	}
487
488	static void draw_tile(frontend fe, game_state state, int x, int y,
489	int tile, int flash_colour)
490	{
491	if (tile == 0) {
492	draw_rect(fe, x, y, TILE_SIZE, TILE_SIZE,
493	flash_colour);
494	} else {
495	int coords[6];
496	char str[40];
497
498	coords[0] = x + TILE_SIZE - 1;
499	coords[1] = y + TILE_SIZE - 1;
500	coords[2] = x + TILE_SIZE - 1;
501	coords[3] = y;
502	coords[4] = x;
503	coords[5] = y + TILE_SIZE - 1;
504	draw_polygon(fe, coords, 3, TRUE, COL_LOWLIGHT);
505	draw_polygon(fe, coords, 3, FALSE, COL_LOWLIGHT);
506
507	coords[0] = x;
508	coords[1] = y;
509	draw_polygon(fe, coords, 3, TRUE, COL_HIGHLIGHT);
510	draw_polygon(fe, coords, 3, FALSE, COL_HIGHLIGHT);
511
512	draw_rect(fe, x + HIGHLIGHT_WIDTH, y + HIGHLIGHT_WIDTH,
513	TILE_SIZE - 2HIGHLIGHT_WIDTH, TILE_SIZE - 2HIGHLIGHT_WIDTH,
514	flash_colour);
515
516	sprintf(str, "%d", tile);
517	draw_text(fe, x + TILE_SIZE/2, y + TILE_SIZE/2,
518	FONT_VARIABLE, TILE_SIZE/3, ALIGN_VCENTRE \| ALIGN_HCENTRE,
519	COL_TEXT, str);
520	}
521	draw_update(fe, x, y, TILE_SIZE, TILE_SIZE);
522	}
523
524	static void draw_arrow(frontend *fe, int x, int y, int xdx, int xdy)
525	{
526	int coords[14];
527	int ydy = -xdx, ydx = xdy;
528
529	#define POINT(n, xx, yy) ( \
530	coords[2(n)+0] = x + (xx)xdx + (yy)*ydx, \
531	coords[2(n)+1] = y + (xx)xdy + (yy)*ydy)
532
533	POINT(0, TILE_SIZE / 2, 3 * TILE_SIZE / 4); /* top of arrow */
534	POINT(1, 3 * TILE_SIZE / 4, TILE_SIZE / 2); /* right corner */
535	POINT(2, 5 * TILE_SIZE / 8, TILE_SIZE / 2); /* right concave */
536	POINT(3, 5 * TILE_SIZE / 8, TILE_SIZE / 4); /* bottom right */
537	POINT(4, 3 * TILE_SIZE / 8, TILE_SIZE / 4); /* bottom left */
538	POINT(5, 3 * TILE_SIZE / 8, TILE_SIZE / 2); /* left concave */
539	POINT(6, TILE_SIZE / 4, TILE_SIZE / 2); /* left corner */
540
541	draw_polygon(fe, coords, 7, TRUE, COL_LOWLIGHT);
542	draw_polygon(fe, coords, 7, FALSE, COL_TEXT);
543	}
544
545	void game_redraw(frontend fe, game_drawstate ds, game_state *oldstate,
74a4e547	546	game_state state, game_ui ui,
74a4e547	547	float animtime, float flashtime)
4efb3868	548	{
b443c381	549	int i, bgcolour;
4efb3868	550
	551	if (flashtime > 0) {
	552	int frame = (int)(flashtime / FLASH_FRAME);
	553	bgcolour = (frame % 2 ? COL_LOWLIGHT : COL_HIGHLIGHT);
	554	} else
	555	bgcolour = COL_BACKGROUND;
	556
	557	if (!ds->started) {
	558	int coords[6];
	559
	560	draw_rect(fe, 0, 0,
	561	TILE_SIZE * state->w + 2 * BORDER,
	562	TILE_SIZE * state->h + 2 * BORDER, COL_BACKGROUND);
	563	draw_update(fe, 0, 0,
	564	TILE_SIZE * state->w + 2 * BORDER,
	565	TILE_SIZE * state->h + 2 * BORDER);
	566
	567	/*
	568	* Recessed area containing the whole puzzle.
	569	*/
	570	coords[0] = COORD(state->w) + HIGHLIGHT_WIDTH - 1;
	571	coords[1] = COORD(state->h) + HIGHLIGHT_WIDTH - 1;
	572	coords[2] = COORD(state->w) + HIGHLIGHT_WIDTH - 1;
	573	coords[3] = COORD(0) - HIGHLIGHT_WIDTH;
	574	coords[4] = COORD(0) - HIGHLIGHT_WIDTH;
	575	coords[5] = COORD(state->h) + HIGHLIGHT_WIDTH - 1;
	576	draw_polygon(fe, coords, 3, TRUE, COL_HIGHLIGHT);
	577	draw_polygon(fe, coords, 3, FALSE, COL_HIGHLIGHT);
	578
	579	coords[1] = COORD(0) - HIGHLIGHT_WIDTH;
	580	coords[0] = COORD(0) - HIGHLIGHT_WIDTH;
	581	draw_polygon(fe, coords, 3, TRUE, COL_LOWLIGHT);
	582	draw_polygon(fe, coords, 3, FALSE, COL_LOWLIGHT);
	583
	584	/*
	585	* Arrows for making moves.
	586	*/
	587	for (i = 0; i < state->w; i++) {
	588	draw_arrow(fe, COORD(i), COORD(0), +1, 0);
	589	draw_arrow(fe, COORD(i+1), COORD(state->h), -1, 0);
	590	}
	591	for (i = 0; i < state->h; i++) {
	592	draw_arrow(fe, COORD(state->w), COORD(i), 0, +1);
	593	draw_arrow(fe, COORD(0), COORD(i+1), 0, -1);
	594	}
	595
	596	ds->started = TRUE;
	597	}
	598
	599	/*
b443c381	600	* Now draw each tile.
4efb3868	601	*/
	602
	603	clip(fe, COORD(0), COORD(0), TILE_SIZEstate->w, TILE_SIZEstate->h);
	604
b443c381	605	for (i = 0; i < state->n; i++) {
	606	int t, t0;
	607	/*
	608	* Figure out what should be displayed at this
	609	* location. It's either a simple tile, or it's a
	610	* transition between two tiles (in which case we say
	611	* -1 because it must always be drawn).
	612	*/
	613
	614	if (oldstate && oldstate->tiles[i] != state->tiles[i])
	615	t = -1;
	616	else
	617	t = state->tiles[i];
	618
	619	t0 = t;
	620
	621	if (ds->bgcolour != bgcolour \|\| /* always redraw when flashing */
	622	ds->tiles[i] != t \|\| ds->tiles[i] == -1 \|\| t == -1) {
	623	int x, y, x2, y2;
	624
	625	/*
	626	* Figure out what to _actually_ draw, and where to
	627	* draw it.
	628	*/
	629	if (t == -1) {
	630	int x0, y0, x1, y1, dx, dy;
	631	int j;
	632	float c;
	633	int sense;
	634
	635	if (oldstate && state->movecount < oldstate->movecount)
	636	sense = -oldstate->last_movement_sense;
	637	else
	638	sense = state->last_movement_sense;
	639
	640	t = state->tiles[i];
	641
	642	/*
	643	* FIXME: must be prepared to draw a double
	644	* tile in some situations.
	645	*/
	646
	647	/*
	648	* Find the coordinates of this tile in the old and
	649	* new states.
	650	*/
	651	x1 = COORD(X(state, i));
	652	y1 = COORD(Y(state, i));
	653	for (j = 0; j < oldstate->n; j++)
	654	if (oldstate->tiles[j] == state->tiles[i])
	655	break;
	656	assert(j < oldstate->n);
	657	x0 = COORD(X(state, j));
	658	y0 = COORD(Y(state, j));
	659
	660	dx = (x1 - x0);
	661	if (dx != 0 &&
	662	dx != TILE_SIZE * sense) {
	663	dx = (dx < 0 ? dx + TILE_SIZE * state->w :
	664	dx - TILE_SIZE * state->w);
	665	assert(abs(dx) == TILE_SIZE);
	666	}
	667	dy = (y1 - y0);
	668	if (dy != 0 &&
669	dy != TILE_SIZE * sense) {
670	dy = (dy < 0 ? dy + TILE_SIZE * state->h :
671	dy - TILE_SIZE * state->h);
672	assert(abs(dy) == TILE_SIZE);
673	}
674
675	c = (animtime / ANIM_TIME);
676	if (c < 0.0F) c = 0.0F;
677	if (c > 1.0F) c = 1.0F;
678
679	x = x0 + (int)(c * dx);
680	y = y0 + (int)(c * dy);
681	x2 = x1 - dx + (int)(c * dx);
682	y2 = y1 - dy + (int)(c * dy);
683	} else {
684	x = COORD(X(state, i));
685	y = COORD(Y(state, i));
686	x2 = y2 = -1;
687	}
688
689	draw_tile(fe, state, x, y, t, bgcolour);
690	if (x2 != -1 \|\| y2 != -1)
691	draw_tile(fe, state, x2, y2, t, bgcolour);
692	}
693	ds->tiles[i] = t0;
4efb3868	694	}
	695
	696	unclip(fe);
	697
	698	ds->bgcolour = bgcolour;
fd1a1a2b	699
	700	/*
	701	* Update the status bar.
	702	*/
	703	{
	704	char statusbuf[256];
	705
d108c342	706	/*
	707	* Don't show the new status until we're also showing the
	708	* new _state_ - after the game animation is complete.
	709	*/
	710	if (oldstate)
	711	state = oldstate;
	712
fd1a1a2b	713	sprintf(statusbuf, "%sMoves: %d",
	714	(state->completed ? "COMPLETED! " : ""),
	715	(state->completed ? state->completed : state->movecount));
	716
	717	status_bar(fe, statusbuf);
	718	}
4efb3868	719	}
	720
	721	float game_anim_length(game_state oldstate, game_state newstate)
	722	{
	723	return ANIM_TIME;
	724	}
	725
	726	float game_flash_length(game_state oldstate, game_state newstate)
	727	{
	728	if (!oldstate->completed && newstate->completed)
	729	return 2 * FLASH_FRAME;
	730	else
	731	return 0.0F;
	732	}
fd1a1a2b	733
	734	int game_wants_statusbar(void)
	735	{
	736	return TRUE;
	737	}